The following invention relates to a bandsaw sharpening machine and in particular to an indexing system to be used with this type of machine to advance the bandsaw one tooth at a time and hold it in position for a regrinding operation.
Bandsaw blades of the type that are frequently used in lumber mills consist of large steel loops having carbide tipped teeth forming an outer edge of the steel band. Periodically such bandsaw blades must be resharpened, and there exist sharpening machines which regrind bandsaw blades a tooth at a time. Typically the bandsaw blade is placed within an oval series of guides or tracks and advanced one tooth at a time relative to a pair of side grinding wheels, or a top and face grinding wheel, for a resharpening operation. Once all of the teeth of the blade have passed through the grinding station, the sharpening operation is complete. Such machines typically advance the blade by using a ratchet or a pawl which engages the scalloped areas of the teeth and pushes the blade in a forward direction. The problem with such devices is that the indexing pawl is highly inaccurate. The teeth are not placed in the proper position in the path of the grinding wheels and this results in inaccuracies in machining. Additionally, with a typical regrinding machine, there is nothing to hold the blade still except for the weight of the blade itself in the guide or track while the grinding wheels engage a tooth. For accurate grinding, however, it is essential that the blade be advanced to the precise position required for engagement by the grinding wheels, and that once in position, the blade be kept perfectly still while the grinding operation takes place.